UC3844BD1R2G from onsemi, in a SOIC-8-150mil. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	Compensation	output	Error-amplifier output / loop compensation node. Available for external loop-compensation networks connected to the Voltage Feedback pin. Also drives the internal current-sense comparator through a 2 V level shift and 1/3 divider.
2	Voltage Feedback	input	Inverting input of the error amplifier. Normally connected to the switching-power-supply output through a resistor divider; internally referenced to 2.5 V. Input bias current typically -0.1 uA.
3	Current Sense	input	Current-sense comparator input. A voltage proportional to primary switch current (via a ground-referenced sense resistor) is applied here. Trips PWM latch when it reaches 1.0 V (typ) scaled from the compensation pin; input range -0.3 to +5.5 V.
4	RT/CT	passive	Oscillator timing pin. An external resistor to Vref and capacitor to GND set the oscillator frequency (fOSC ~ 1.72/(RT*CT) for RT > 5 k) and output deadtime. Guaranteed to 250 kHz; usable to 500 kHz output switching frequency.
5	GND	power_in	Device ground (control and power ground shared in the 8-pin package). Return for all internal circuitry and the totem-pole output stage.
6	Output	output	High-current totem-pole output for driving a power MOSFET gate directly. Rated for 1.0 A source/sink peak; typical rise/fall time 50 ns with 1 nF load. Duty cycle limited to 50% max (UC3844B/UC2844B).
7	VCC	power_in	Positive supply for control logic and output driver. UVLO on/off thresholds 16 V / 10 V (UC3844B). Absolute maximum 36 V; internal zener clamp at ~36 V (IZ up to 25 mA). Startup current ~0.5 mA, operating ~17 mA.
8	Vref	power_out	5.0 V trimmed reference output (+/-1% at 25 C). Sources up to 20 mA for external circuitry and the oscillator timing resistor; short-circuit current typically -85 mA.

Key specifications

Parameter	Value
Manufacturer	onsemi
Package	SOIC-8-150mil
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

UC3844BD1R2G
UC3844BD1R2GD1G
UC3844BD1R2GN
UC3844BD1R2GNG
UC3844BD1R2GD
UC3844BD1R2GDR2G
UC3844BD1R2GDG

CAD (KiCad official)

Symbol: UC3844BD1R2G
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8-150mil (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`uc3844bd1r2g.step`	122 KB	You want the bare part, or you mark your own boards.
`uc3844bd1r2g-etched.step`	2.7 MB	You want the part with `UC3844BD1R2G` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 665 faces against 147 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: onsemi datasheet (19 pp, sha256 e69ff39fc0ea9e08, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF